Contact Lenses
Are Contact Lenses Right For Me?
We’ve all heard of contact lenses, and the majority of us know someone who wears them, but the questions remain; what types of vision correction can they provide, and is everyone a candidate? The answers to both of these questions are, “It depends.”
First, if you are younger than 40 and wear contact lenses, you probably won’t understand the following explanation, so enjoy your perfect vision for now…..your time will come.
Benefits of Contact Lenses over Spectacles
As far as visual correction is concerned, contact lenses can typically provide equal or better vision than spectacles for a given distance. By a “given distance” we mean either near, intermediate, or far, but typically not a combination of all three (unless you’re younger than 40 and still have plenty of focusing power left) with a given contact lens. The reason for this disparity is due to the fact that the optic zone (where your prescription is) of the contact lens typically moves with the eye when you look around, as opposed to spectacles, where the power may vary depending on lens location, i.e. progressives or bifocals. With a soft contact lens you are always looking through the center of the lens regardless of whether or not you are viewing your computer, television, or smart phone. So if you’re over 40 and know that your prescription varies depending on the distance of a given target, you can see why soft contact lenses can be difficult. Years ago, soft contact lenses suffered from poor compound optics and weren’t capable of providing acceptable vision at multiple distances, but technology and optics design have improved and soft lenses do a pretty good job at correcting multiple distances for people who need presbyopic correction.
Hard Lenses
As far as the hard lens or gas permeable wearers are concerned, they actually have an advantage over soft lens wearers when it comes to providing good distance, intermediate, and near vision. Hard lenses typically have better optics than soft lenses due to the fact that they “float” on the cornea (the clear front surface of your eye). This allows any irregularity in your cornea to be filled in by your tears and the smooth back surface of the hard lens, thus creating a “custom tear lens” on the surface of your eye that would be impossible to duplicate in spectacles or soft contact lenses. Hard lenses also glide upwards on the cornea when the wearer looks down, as opposed to soft lenses which essentially suction to the cornea. Because of the gliding motion of hard lenses, we can manufacture different optics into different parts of the contact lens to provide optimal near, intermediate, and distance vision, which can sometimes rival or exceed that of spectacles.
Advantages of Hard Lenses
Hard lenses also have the advantage of correcting relatively large amounts of corneal astigmatism without any deleterious effect to vision that one might have with astigmatic soft lenses. Corneal astigmatism, in it’s simplest form, is simply a difference in the curvature over the surface of the cornea. If someone has corneal astigmatism, and we measure the curvature of their cornea from the 3-9 oclock (horizontal) meridian and compare that measurement to the 12-6 o’clock (vertical) meridian, those numbers would be different. Someone who has zero corneal astigmatism, would have the same curvature reading along all the meridians of the cornea, i.e. their cornea would be perfectly round or “spherical.”
Hard lenses will again float on the surface of the cornea and the natural tears on the front of the eye will fill in the different areas of curvature to correct the corneal astigmatism. Soft lenses do not float on the surface, they drape over the cornea and must correct astigmatism with varying thickness to the edge of the lens and power throughout. If you can imagine, a soft lens that rotates slightly on the surface of the eye would therefore distort the optics of the wearers correction, whereas a hard lens can rotate all day long and not distort the vision due to the custom ever changing “tear lens” that lies in between the hard lens and the cornea. For this reason, soft lenses that correct astigmatism must be very still on the eye to work well, and this is why they don’t work well at correcting vision at multiple distances for patients over 40 years of age.
How Monovision Contact Lenses Can Help
One of the most successful and well established methods of providing good distance and near vision with contact lenses is wearing different powers for different distances, also known as monovision. Monovision has the advantage of providing excellent acuity at either near or far, but typically not in between. Nowadays, with most people spending more than a few hours on a computer each day, we can get by not having perfect near vision, as long as our computer screen is clear and we can read signs while driving. Because the brain goes from using both eyes for distance and near, to using one eye for each distance, it can take some getting used to. Monovision also has the potential to decrease some depth perception, and so may not be the best idea for those in certain careers, i.e. pilots or law enforcement. Monovision can be fit with either soft spherical, rgp, or astigmatism contact lenses.
Improving The Technology of Contact Lenses
The contact lens companies are always working on new designs for multifocal contact lenses, and they’ll continue to pool research dollars into that area. If you think about it, nearly all of us need some sort of visual correction past 45, whether it be just reading glasses or distance glasses. If you want to be totally glasses free, multifocal or monovision contact lenses may be the answer for you.
Both Dr. Willson and myself really enjoy fitting and working with our friends to come up with the most personalized contact lens prescription to give our patients the greatest visual freedom we can from their glasses. After all, there’s nothing visually better than wearing a regular pair of sunglasses while sitting at the beach, and having the ability to easily read your book and seeing the smiles of your family playing in the surf.
If you need contact lenses in Orlando, call the Orlando optometrists at Maitland Vision Center today!
We’ve all heard of contact lenses, and the majority of us know someone who wears them, but the questions remain; what types of vision correction can they provide, and is everyone a candidate? The answers to both of these questions are, “It depends.”
First, if you are younger than 40 and wear contact lenses, you probably won’t understand the following explanation, so enjoy your perfect vision for now…..your time will come.
Benefits of Contact Lenses over Spectacles
As far as visual correction is concerned, contact lenses can typically provide equal or better vision than spectacles for a given distance. By a “given distance” we mean either near, intermediate, or far, but typically not a combination of all three (unless you’re younger than 40 and still have plenty of focusing power left) with a given contact lens. The reason for this disparity is due to the fact that the optic zone (where your prescription is) of the contact lens typically moves with the eye when you look around, as opposed to spectacles, where the power may vary depending on lens location, i.e. progressives or bifocals. With a soft contact lens you are always looking through the center of the lens regardless of whether or not you are viewing your computer, television, or smart phone. So if you’re over 40 and know that your prescription varies depending on the distance of a given target, you can see why soft contact lenses can be difficult. Years ago, soft contact lenses suffered from poor compound optics and weren’t capable of providing acceptable vision at multiple distances, but technology and optics design have improved and soft lenses do a pretty good job at correcting multiple distances for people who need presbyopic correction.
Hard Lenses
As far as the hard lens or gas permeable wearers are concerned, they actually have an advantage over soft lens wearers when it comes to providing good distance, intermediate, and near vision. Hard lenses typically have better optics than soft lenses due to the fact that they “float” on the cornea (the clear front surface of your eye). This allows any irregularity in your cornea to be filled in by your tears and the smooth back surface of the hard lens, thus creating a “custom tear lens” on the surface of your eye that would be impossible to duplicate in spectacles or soft contact lenses. Hard lenses also glide upwards on the cornea when the wearer looks down, as opposed to soft lenses which essentially suction to the cornea. Because of the gliding motion of hard lenses, we can manufacture different optics into different parts of the contact lens to provide optimal near, intermediate, and distance vision, which can sometimes rival or exceed that of spectacles.
Advantages of Hard Lenses
Hard lenses also have the advantage of correcting relatively large amounts of corneal astigmatism without any deleterious effect to vision that one might have with astigmatic soft lenses. Corneal astigmatism, in it’s simplest form, is simply a difference in the curvature over the surface of the cornea. If someone has corneal astigmatism, and we measure the curvature of their cornea from the 3-9 oclock (horizontal) meridian and compare that measurement to the 12-6 o’clock (vertical) meridian, those numbers would be different. Someone who has zero corneal astigmatism, would have the same curvature reading along all the meridians of the cornea, i.e. their cornea would be perfectly round or “spherical.”
Hard lenses will again float on the surface of the cornea and the natural tears on the front of the eye will fill in the different areas of curvature to correct the corneal astigmatism. Soft lenses do not float on the surface, they drape over the cornea and must correct astigmatism with varying thickness to the edge of the lens and power throughout. If you can imagine, a soft lens that rotates slightly on the surface of the eye would therefore distort the optics of the wearers correction, whereas a hard lens can rotate all day long and not distort the vision due to the custom ever changing “tear lens” that lies in between the hard lens and the cornea. For this reason, soft lenses that correct astigmatism must be very still on the eye to work well, and this is why they don’t work well at correcting vision at multiple distances for patients over 40 years of age.
How Monovision Contact Lenses Can Help
One of the most successful and well established methods of providing good distance and near vision with contact lenses is wearing different powers for different distances, also known as monovision. Monovision has the advantage of providing excellent acuity at either near or far, but typically not in between. Nowadays, with most people spending more than a few hours on a computer each day, we can get by not having perfect near vision, as long as our computer screen is clear and we can read signs while driving. Because the brain goes from using both eyes for distance and near, to using one eye for each distance, it can take some getting used to. Monovision also has the potential to decrease some depth perception, and so may not be the best idea for those in certain careers, i.e. pilots or law enforcement. Monovision can be fit with either soft spherical, rgp, or astigmatism contact lenses.
Improving The Technology of Contact Lenses
The contact lens companies are always working on new designs for multifocal contact lenses, and they’ll continue to pool research dollars into that area. If you think about it, nearly all of us need some sort of visual correction past 45, whether it be just reading glasses or distance glasses. If you want to be totally glasses free, multifocal or monovision contact lenses may be the answer for you.
Both Dr. Willson and myself really enjoy fitting and working with our friends to come up with the most personalized contact lens prescription to give our patients the greatest visual freedom we can from their glasses. After all, there’s nothing visually better than wearing a regular pair of sunglasses while sitting at the beach, and having the ability to easily read your book and seeing the smiles of your family playing in the surf.
If you need contact lenses in Orlando, call the Orlando optometrists at Maitland Vision Center today!